Hi,
I am a PhD student who has precisely finished her second year of PhD. I have a master degree in mathematics and now my PhD is in informatics and computer science. I feel like I have lost all my skills in mathematics and I can't learn new material in computer science. I have hard time to learn new concepts in computer science. I have not gone forward since last year and my progress is not satisfying and I am very worried about that. Sometimes I feel like I have forgotten even basic mathematics. I am very worriedabout not being able to finish my PhD.
I appreciate if some one can help me and give some advice.

First of all TAKE A DEEP BREATHE. 2) THERE IS A REASON WHY YOU ARE SECOND YEAR 3) PANICKING DOESNT HELP 4) TAKE A STEP BACK AND CRITICALLY EVALUATE WERE YOUTRPHD OBJECTIVES, WERE YOU STARTED IN YOUR FIRST YEAR AND CURRENT STATUS AND PENDING WORK. THIS WILL TAKE A DAY OR TWO. SO LAY BACK AND DONT DO ANY WORK FOR 2DAYS AND CRITICALLY EVALUATE YOUR CURRENT STAGE AND WRITE GOALS AND GIVE YOURSELF DEADLINES.

Hi asallili, I know how you feel. I too have just recently completed my second year. I only have one experimental chapter completed and am still collecting data for my second proper experiment. My whole first year was taken up by reading/researching my methodology and forming questions, so it was only really in the middle of the second year that I started properly collecting data. I think what derose says is right, just look back on your goals and what you have achieved so far. Also, I find it helps if I write as much as possible, it helps in showing that you are progressing. Keep going and we'll get there in the end